WO2017217534A1

WO2017217534A1 - Test object visualizing device

Info

Publication number: WO2017217534A1
Application number: PCT/JP2017/022295
Authority: WO
Inventors: 昌宏戸井田
Original assignee: 学校法人埼玉医科大学
Priority date: 2016-06-17
Filing date: 2017-06-16
Publication date: 2017-12-21
Also published as: EP3474001B1; EP3474001A4; JPWO2017217534A1; US20190137402A1; JP6804773B2; US10809200B2; EP3474001A1

Abstract

This test object visualizing device includes: a light radiating unit which, for each inspection site on the test object, radiates pump light and Stokes light, generated on the same optical path, at a test object, with the wavelength of at least one of the pump light and the Stokes light variable; a molecular distribution image generating unit which detects anti-Stokes light arising from the test object in accordance with the difference in the wavelengths of the pump light and the Stokes light, and generates a molecular distribution image on the basis of the anti-Stokes light; a tomographic image generating unit which detects at least one of reflected light from the test object when irradiated with the pump light, and reflected light from the test object when irradiated with the Stokes light, and generates a tomographic image of the test object on the basis of the detected reflected light; and an image display unit which displays at least one of the generated molecular distribution image and the generated tomographic image.

Description

Subject visualization device

The present invention relates to a test subject visualization apparatus that visualizes a molecular distribution image and a cross section of a test subject.

In recent years, genetic diagnosis has made great strides, and it has become an era when it is possible to determine individually what disease risk is genetically. However, since it is not known until the time of the occurrence of the disease, it is important to detect the occurrence of the disease at an early stage by a less invasive method and realize a treatment with less invasiveness.

For early detection of illness, it is important to capture functional changes in the previous stages leading to morphological changes in the test subject. In order to capture the functional change, a molecular distribution imaging technique capable of visualizing the distribution of a specific protein or the like in a cell or tissue while the tissue structure is alive (in vivo) is effective.

The molecular distribution imaging technique using light is roughly classified into a probe method using a fluorescent labeling agent and the like, and a non-probe method using the characteristics of the in-vivo substance. Among the non-probe methods, the molecular distribution imaging technique using CARS (Coherent Anti-Stokes Raman Scattering) has been studied.
Moreover, in elucidating the onset mechanism of various diseases and the mechanism of their development, in order to capture the morphological change of the test subject, detailed spatial position information of the molecule of the test subject is essential. For this reason, the molecular distribution imaging technique according to the spatial position information is required.

The spatial position information can be obtained, and OCT (Optical Coherence Tomography) has been developed as a noninvasive morphological imaging technique. Then, the compounding of the molecular distribution imaging technique using the CARS and the morphological imaging technique using the OCT has been studied, and the inventor has also proposed (for example, see Patent Document 1).

JP2015-141282A

This invention makes it a subject to solve the said various problems in the past and to achieve the following objectives. That is, an object of the present invention is to provide a test subject visualization apparatus that can simultaneously acquire a molecular distribution image image and a tomographic image of a test subject.

Means for solving the problems are as follows. That is,
<1> A light irradiation unit that varies at least one of the wavelengths of the pump light and the Stokes light generated in the same optical path for each test location of the test target, and irradiates the test target with the pump light and the Stokes light. ,
A molecular distribution image image generation unit that detects anti-Stokes light generated from the test object according to a wavelength difference between the pump light and the Stokes light, and generates a molecular distribution image image based on the anti-Stokes light;
Detecting at least one of reflected light from the test subject when irradiated with the pump light, and reflected light from the test subject when irradiated with the Stokes light, and based on the detected reflected light A tomographic image generator for generating a tomographic image of the test object;
A test object visualization apparatus comprising: an image display unit configured to display at least one of the generated molecular distribution image and the tomographic image.

In the test subject visualization device according to <1>, for each test location of the test subject, the light irradiation unit varies the wavelength of at least one of the pump light and the Stokes light generated in the same optical path, The test light is irradiated to the pump light and the Stokes light. The molecular distribution image image generation unit detects the anti-Stokes light generated from the test object according to a wavelength difference between the pump light and the Stokes light, and generates a molecular distribution image image based on the anti-Stokes light. The tomographic image generation unit detects and detects at least one of reflected light from the test subject when irradiated with the pump light and reflected light from the test subject when irradiated with the Stokes light. A tomographic image of the test subject is generated based on the reflected light. The image display unit displays a tomographic image generation unit that generates a tomographic image of the test subject based on the detected reflected light, and at least one of the generated molecular distribution image image and the tomographic image.

Compared with the case where the light irradiation unit generates the pump light and the Stokes light in separate optical paths by generating the pump light and the Stokes light in the same optical path, the optical path from the exit port to the test subject. A mirror or space for adjusting the length becomes unnecessary, and the test object visualization apparatus can be miniaturized.
In addition, the test subject visualization apparatus irradiates the test subject by varying the wavelength of at least one of the pump light and the Stokes light generated in the same optical path for each test location of the test subject. Generating a tomographic image of the test subject based on at least one of reflected light from the test subject when irradiated with the pump light and reflected light from the test subject when irradiated with the Stokes light Since the molecular distribution image is generated based on the anti-Stokes light, the molecular distribution image and the tomographic image can be acquired simultaneously. In addition, the three-dimensional molecular distribution image image and the tomographic image can be acquired by XY scanning the pump light and the Stokes light.

<2> The pump light and the Stokes light so that a wavelength difference between the pump light and the Stokes light becomes 0 in a range in which the light irradiation unit varies the wavelength of the pump light and the wavelength of the Stokes light. Irradiating the subject with light,
Data based on the reflected light from the test subject when the tomographic image generation unit irradiates the pump light, and data based on the reflected light from the test subject when the Stokes light is irradiated, The test object visualization apparatus according to <1>, wherein the tomographic image is generated based on data combined at a wavelength at which the wavelength difference is 0.

In the test subject visualization device according to <2>, the light irradiation unit has a wavelength difference between the pump light and the Stokes light of 0 in a range in which the wavelength of the pump light and the wavelength of the Stokes light are varied. In such a manner, the test light is irradiated with the pump light and the Stokes light. Thereby, the data based on the reflected light from the test subject when the tomographic image generation unit irradiates the pump light and the data based on the reflected light from the test subject when irradiated with the Stokes light Can be increased in the depth direction of the tomographic image, and the resolution of the tomographic image can be increased. can do.

<3> The <1> to <2>, wherein the molecular distribution image image generation unit uses the anti-Stokes light as interference light and performs an inverse Fourier transform calculation process on a spectral interference signal obtained by separating the interference light. It is a test subject visualization apparatus in any one.

In the test subject visualization device according to <3>, the molecular distribution image image generation unit performs an inverse Fourier transform calculation process on a spectral interference signal obtained by separating the interference light using the anti-Stokes light as interference light. By doing so, the molecular distribution image can be generated from the Wiener Hinting theorem.

<4> At least one of the reflected light from the test subject when the tomographic image generating unit irradiates the pump light and the reflected light from the test subject when irradiated with the Stokes light. The test object visualization apparatus according to any one of <1> to <3>, wherein the interference interference light is used to perform inverse Fourier transform processing on a spectral interference signal obtained by separating the interference light.

The test subject visualization device according to <4>, wherein the tomographic image generation unit irradiates the reflected light from the test subject when irradiated with the pump light and the Stokes light. Generating the tomographic image from Wiener Hinchin's theorem by using at least one of the reflected light from the interference light as an interference light and performing an inverse Fourier transform operation on a spectral interference signal obtained by separating the interference light Can do.

<5> The light irradiation unit is
An optical parametric crystal that converts a wavelength of the light according to an incident angle of the light, and an optical confinement device that confines the light;
The subject visualization according to any one of <1> to <4>, further comprising: an optical resonator that shares the optical parametric crystal with the optical confinement device and amplifies light having a wavelength converted by the optical parametric crystal. Device.

In the light irradiation unit of the test subject visualization device according to <5>, the optical confinement device includes an optical parametric crystal that converts a wavelength of the light according to an incident angle of light, and confines the light. The optical resonator shares the optical parametric crystal with the optical confinement device, and amplifies light whose wavelength is converted by the optical parametric crystal. As a result, the angle of the optical parametric crystal with respect to the optical axis direction of the light is changed, and the light converted into two types of wavelengths is amplified by the optical resonator and is used as the pump light and the Stokes light. Can be emitted. Further, the wavelength of the pump light and the wavelength of the Stokes light can be varied by changing the angle of the optical parametric crystal.

<6> The <1> to <5>, wherein the light irradiation unit varies the wavelength of the pump light and the wavelength of the Stokes light so that a vibration band in a molecule included in the test subject coincides with the wavelength difference. The test subject visualization apparatus according to any one of the above.

In the test subject visualization device according to <6>, the light irradiation unit may change the wavelength of the pump light and the wavelength of the Stokes light so that a vibration band in a molecule included in the test subject matches the wavelength difference. By making it variable, the anti-Stokes light can be generated from the molecules of the test subject, and therefore the molecular distribution image can be generated based on the detected anti-Stokes light. Moreover, the molecule | numerator which the said test subject has may be multiple.

<7> The test subject visualization device according to <6>, wherein the molecule of the test subject is at least one of glucose, rutinol, and lutein.

In the test subject visualization device according to <7>, the molecule in the test subject has at least one of glucose, rutinol, and lutein, whereby the intraretinal distribution of molecules involved in the development of age-related macular degeneration Thus, age-related macular degenerative disease can be diagnosed early.

According to the present invention, the conventional problem can be solved, and a test subject visualization apparatus capable of simultaneously obtaining a molecular distribution image and a tomographic image of a test subject can be provided.

FIG. 1A is an explanatory diagram showing an energy level process until anti-Stokes light is generated in CARS. FIG. 1B is an explanatory diagram illustrating a relationship between angular frequencies of pump light, Stokes light, and anti-Stokes light. FIG. 2A is an explanatory diagram showing a resonance process that becomes resonance anti-Stokes light when passing through an excitation level V = 1 of molecular vibration. FIG. 2B is an explanatory diagram showing a non-resonant process that becomes non-resonant anti-Stokes light when the excitation level V = 1 of molecular vibration is not passed. FIG. 3 is a graph showing the dependence of the signal strength of anti-Stokes light on the wavelength of Stokes light when the glucose solution is irradiated with pump light and Stokes light simultaneously. FIG. 4 is an explanatory diagram illustrating a test subject visualization apparatus according to an embodiment. FIG. 5 is an explanatory diagram showing an example of the relationship between the wavelength variable range of the pump light and the Stokes light, the vibration band in the molecule to be tested, and the wavelength of the anti-Stokes light.

(Test object visualization device)
The test object visualization device includes a light irradiation unit, a molecular distribution image image generation unit, a tomographic image generation unit, and an image display unit, and further includes other units as necessary.

<Light irradiation part>
The light irradiation unit varies the wavelength of at least one of pump light and Stokes light generated in the same optical path for each examination location of the test subject, and irradiates the test subject with the pump light and the Stokes light.

There is no restriction | limiting in particular in the said test subject, According to the objective, it can select suitably, For example, a fundus etc. are mentioned.
The said test | inspection location means the location which wants to acquire the said molecular distribution image image and the said tomographic image of the said test object. The pumping light and the Stokes light are simultaneously irradiated on the inspection location. The pump light and the Stokes light are irradiated at the same time, anti-Stokes light is generated according to a wavelength difference between the pump light and the Stokes light, and the molecular distribution image image is generated based on the detected anti-Stokes light. it can.
The wavelength difference means a difference between the wavelength of the pump light and the wavelength of the Stokes light.
Further, when a plurality of the examination locations are set in the X direction of the test subject, the two-dimensional molecular distribution image image and the tomographic image are obtained. A molecular distribution image and the tomographic image can be obtained.
The same optical path means that the light path is the same and passes through the same optical system.
Examples of a method for generating the pump light and the Stokes light in the same optical path include a method using optical parametric oscillation.
Examples of the method based on the optical parametric oscillation include a method of generating laser light having different wavelengths by irradiating a nonlinear medium such as an optical parametric crystal with laser light having a predetermined wavelength.

The pump light is light that is irradiated to the test subject so that the energy level of the molecule that the test subject has in order to generate anti-Stokes light from the molecule that the test subject has, and in optical parametric oscillation Is sometimes referred to as “signal light”.
In order to generate the anti-Stokes light from the molecules of the test subject, the Stokes light induces the energy level of the molecules raised by irradiation with the pump light to a predetermined energy level. This is the light that is irradiated to the object, and is sometimes referred to as “idler light” in optical parametric oscillation.
In addition, the principle which produces the said anti-Stokes light from the molecule | numerator which the said test subject has by irradiating the said test | inspection location of the said test subject simultaneously with the said pump light and the said Stokes light is mentioned later.
The wavelength of at least one of the pump light and the Stokes light is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably 980 nm to 1,150 nm. When the wavelength is within the preferable range, it is advantageous in that the molecular distribution image and the tomographic image can be easily obtained in a deep portion under the fundus retina.

The light irradiation unit transmits the pump light and the Stokes light so that a wavelength difference between the pump light and the Stokes light becomes 0 in a range in which the wavelength of the pump light and the wavelength of the Stokes light are varied. It is preferable to irradiate the test subject.

The light irradiation unit preferably varies the wavelength of the pump light and the wavelength of the Stokes light so that a vibration band in a molecule included in the test subject matches the wavelength difference. Thereby, the said anti-Stokes light can be produced from the molecule | numerator which the said test subject has, the said anti-Stokes light can be detected, and the said molecular distribution image image can be produced | generated.
The test subject may have a plurality of molecules.
The molecule of the test subject is not particularly limited, and a molecule involved in a disease can be appropriately selected according to the purpose.However, in terms of being known to be involved in age-related macular degeneration disease, glucose, It is preferably at least one of rutinol and lutein.

The light irradiator has an optical parametric crystal that converts the wavelength of the light according to the incident angle of light, and shares the optical parametric crystal with the optical confinement device, It is preferable to provide an optical resonator that amplifies the light whose wavelength is converted by the optical parametric crystal.
Thereby, the angle of the optical parametric crystal with respect to the optical axis direction of the light is changed, and the light converted into two kinds of wavelengths in the same optical path is amplified by the optical resonator, and the pump light and the light It is emitted as Stokes light.
Moreover, the wavelength of the pump light and the wavelength of the Stokes light can be varied by changing the angle of the optical parametric crystal. In addition, the efficiency of the optical parametric oscillation, the stability over time, the stability of the emission position of the pump light and the Stokes light with respect to wavelength change are ensured, and the nanosecond pulse, picosecond pulse, and femtosecond pulse Any of the above-mentioned light can be dealt with.

The high efficiency of the optical parametric oscillation is achieved by confining the light by the optical confinement device, allowing the optical parametric crystal to pass through a plurality of times, and ensuring an action length of energy conversion from the light to the pump light and the Stokes light. This is realized.
The temporal stability of the optical parametric oscillation is realized by shortening the resonator length of the optical parametric oscillation. Further, by matching the optical path length in the optical confinement device with the optical path length in the optical resonator, an optical parametric oscillation capable of handling any of the light of nanosecond pulses, picosecond pulses, and femtosecond pulses. To realize.
Further, since the pump light and the Stokes light in the optical resonator reciprocate the optical parametric crystal, the angle of the optical parametric crystal with respect to the optical axis direction of the light is changed, and the light is transmitted in the forward path. Even if the position of the optical axis is shifted, the position of the optical axis returns on the return path, so that the emission positions of the pump light and the Stokes light can be made unchanged.
There is no restriction | limiting in particular as said optical parametric crystal, According to the objective, it can select suitably, For example, potassium titanium phosphate (KTP) etc. are mentioned.

<Molecular distribution image generator>
The molecular distribution image image generation unit detects the anti-Stokes light generated from the molecules of the test object according to a wavelength difference between the pump light and the Stokes light, and the molecular distribution image image based on the anti-Stokes light. Is generated.
It is preferable that the molecular distribution image image generation unit performs an inverse Fourier transform calculation process on a spectral interference signal obtained by using the anti-Stokes light as interference light and separating the interference light.

The anti-Stokes light is preferably generated from a molecule of the test subject by, for example, CARS (Coherent Anti-Stokes Raman Scattering).
Next, the CARS will be described with reference to FIGS. 1A, 1B, 2A, and 2B.

FIG. 1A is an explanatory diagram showing an energy level process until anti-Stokes light is generated in CARS.
As shown in FIG. 1A, pulsed-oscillated pump light (angular frequency ω _p ) and pulse-oscillated Stokes light (angular frequency ω _s ) are simultaneously and temporally irradiated onto the test subject. At this time, if the angular frequency difference (Δω = ω _p −ω _s ) between the pump light and the Stokes light is a vibration band in the molecule to be tested, the energy level of the molecule is changed to the base level by the pump light. While rising from the level V = 0 to the upper level, the Stokes light induces the excitation level V = 1. Thereafter, when the test light is irradiated onto the test subject, anti-Stokes light is generated in the process of lowering to the ground level V = 0 after rising to a higher level.
The width of the pulse in the pump light and the width of the pulse in the Stokes light are not particularly limited and may be appropriately selected depending on the purpose, but are preferably in the order of picoseconds. This makes the test subject non-invasive and facilitates ensuring a ratio of the resonance signal to the non-resonance signal (hereinafter also referred to as “resonance signal / non-resonance signal ratio”).

FIG. 1B is an explanatory diagram illustrating a relationship between angular frequencies of pump light, Stokes light, and anti-Stokes light.
As shown in FIG. 1B, the angular frequency ω _s of the Stokes light and the angular frequency ω _as of the anti-Stokes light are separated from each other by ± Δω centered on the angular frequency ω _p of the pump light from the relationship of energy levels. Exists. That is, the angular frequency of the Stokes light can be expressed by the following equation: ω _s = ω _p −Δω. The angular frequency of the anti-Stokes light can be expressed by the following equation: ω _as = 2ω _p −ω _s = ω _p + Δω.

FIG. 2A is an explanatory diagram showing a resonance process that becomes resonance anti-Stokes light when passing through an excitation level V = 1 of molecular vibration. FIG. 2B is an explanatory diagram showing a non-resonant process that becomes non-resonant anti-Stokes light when the excitation level V = 1 of molecular vibration is not passed.
As shown in FIGS. 2A and 2B, the anti-Stokes light includes the resonance anti-Stokes light (hereinafter sometimes referred to as “resonance signal” or simply “anti-Stokes light”) and the non-resonance anti-Stokes light ( Hereinafter, there are two types of “non-resonant signals”.
The resonance anti-Stokes light generated through the resonance process is generated from molecules of the test object and is used when generating the molecular distribution image.
The non-resonant anti-Stokes light generated through the non-resonant process is a response that is almost independent of the wavelength difference and involves the electronic excitation of water.

<Tomographic image generator>
The tomographic image generation unit detects and detects at least one of reflected light from the test subject when irradiated with the pump light and reflected light from the test subject when irradiated with the Stokes light. A tomographic image of the test subject is generated based on the reflected light.
The tomographic image can be acquired by, for example, OCT (Optical Coherence Tomography) or the like, and SS-OCT (Swept Source Optical Coherence Tomography) is preferable.
The tomographic image generation unit uses interference light as at least one of the reflected light from the test subject when irradiated with the pump light and the reflected light from the test subject when irradiated with the Stokes light. It is preferable to perform an inverse Fourier transform calculation process on the spectral interference signal obtained by separating the interference light.

<Image display section>
The image display unit displays at least one of the generated molecular distribution image and the tomographic image.
There is no restriction | limiting in particular as said image display part, According to the objective, it can select suitably, For example, a liquid crystal monitor etc. are mentioned.

<Other parts>
There is no restriction | limiting in particular as said other part, Although it can select suitably according to the objective, It is preferable to have a signal processing part.
The signal processing unit is not particularly limited and may be appropriately selected depending on the purpose. However, the signal processing unit irradiates data based on the reflected light from the test subject when the pump light is irradiated and the Stokes light. It is preferable to combine the data based on the reflected light from the subject under test at a wavelength where the wavelength difference is zero.

FIG. 3 is a graph showing the dependence of the signal intensity of the anti-Stokes light on the wavelength of the Stokes light when the glucose solution is simultaneously irradiated with the pump light and the Stokes light, and the vertical axis represents the anti-Stokes light. The signal intensity (mV), and the horizontal axis represents the wavelength (nm) of the Stokes light. In FIG. 3, the wavelength of the pump light is fixed to 1,064 nm, the wavelength of the Stokes light is changed, and the signal intensity of the anti-Stokes light from the glucose solution is plotted.
As shown in FIG. 3, it can be confirmed that the signal strength of the anti-Stokes light does not decrease in the range of ± 6 nm centered at 1,209 nm in the wavelength of the Stokes light. From this, the resolution in the optical axis direction of the anti-Stokes light can be ensured by detecting the anti-Stokes light as the spectral interference signal in a range of about 10 nm while sweeping the wavelength of the Stokes light. Further, by detecting the reflected light of the Stokes light as the spectral interference signal while sweeping the wavelength of the Stokes light, a spectral interference signal in the depth direction (hereinafter referred to as “A” in SS-OCT (Swept Source Optical Coherence Tomography)). In other words, the tomographic image can be generated.

Examples of the present invention will be described below, but the present invention is not limited to these examples.

FIG. 4 is an explanatory diagram illustrating a test subject visualization apparatus according to an embodiment.
As shown in FIG. 4, the test subject visualization apparatus 10 includes a light irradiation unit 100, a molecular distribution image image generation unit 200, a tomographic image generation unit 300, a signal processing unit 400, and an image display unit 500. .
The fundamental laser 101 of the light irradiation unit 100 emits a laser beam having a wavelength of 1,064 nm to the dichroic mirror 102. The laser beam is a mode-locked laser beam in which picosecond or femtosecond modes are synchronized.

The dichroic mirror 102 has non-reflective characteristics with respect to light having a wavelength of 1,064 nm on the S1 surface. The dichroic mirror 102 has non-reflective characteristics with respect to light having a wavelength of 1,064 nm and total reflection characteristics with respect to light having a wavelength of 532 nm on the S2 surface.

The dichroic mirror 105 has non-reflective characteristics with respect to light having a wavelength of 532 nm on the S3 surface. Further, the dichroic mirror 105 has total reflection characteristics with respect to light having a wavelength of 900 nm to 1,200 nm and non-reflection characteristics with respect to light having a wavelength of 532 nm on the S4 surface.

The total reflection mirror 109 has total reflection characteristics with respect to light having a wavelength of 900 nm to 1,200 nm on the S5 surface.

The output mirror 111 has 70% PR (Partial Reflection) characteristics for light with a wavelength of 900 nm to 1,200 nm and total reflection characteristics for light with a wavelength of 532 nm on the S6 surface. The output mirror 111 has non-reflective characteristics with respect to light having a wavelength of 900 nm to 1,200 nm on the S7 surface.

A space between the dichroic mirror 102 and the total reflection mirror 109 forms an optical confinement device (Cavity) that confines light having a wavelength of 532 nm.
Note that the optical path length of the optical confinement device can be controlled by providing the dichroic mirror 102 on the moving stage 103.

An L-shaped space formed by the total reflection mirror 109, the dichroic mirror 105, and the output mirror 111 forms an optical resonator (Optical Parametric Oscillation Cavity).
In the optical resonator, each time light having a wavelength of 532 nm passes through the optical parametric crystal 106 in the same optical path, the signal light and the idler light are amplified, and the signal light and the idler light exceeding the threshold of the output mirror 111 are amplified. Are emitted from the output mirror 111 as the pump light (indicated by a dotted arrow in FIG. 4) and the Stokes light (indicated by a broken arrow in FIG. 4).
The optical confinement device and the optical resonator share the optical parametric crystal 106. Further, since the total reflection mirror 109 is provided on the moving stage 110, the optical path length of the optical resonator can be controlled. Further, the wavelength of the pump light and the wavelength of the Stokes light generated in the same optical path are changed by changing the angle of the optical parametric crystal 106 using the galvano motor 107 to which the galvano drive signal is input from the galvano power supply 108. , Each can be varied.

Due to the moving

stages

103 and 110, the time for light having a wavelength of 532 nm to reciprocate through the optical confinement device and the time to reciprocate through the optical resonator are matched, and a plurality of optical parametric crystals 106 are formed within one light pulse period. Excited through multiple passes.

Due to the optical parametric oscillation, the pump light and the Stokes light are emitted from the output mirror 111 in a state where they are overlapped spatially and temporally in orthogonal polarization directions.
The pump light and the Stokes light having two orthogonal polarization frequencies are passed through a polarizer 112 whose optical axis direction is inclined by 45 ° with respect to the orthogonal axis, whereby the pump light and the Stokes light whose polarization directions coincide with each other at 45 °. Become light.

Next, a tomographic image acquisition operation will be described.
The pump light and the Stokes light whose polarization directions coincide with the 45 ° direction are each split by the half mirror 113.

One of the pump light and the Stokes light bisected by the half mirror 113 is incident on the fundus of the eyeball unit 20 as the test object via the galvanometer mirrors 115 and 116, and at the refractive index boundary of the eyeball unit 20. The light is reflected, and is incident on the half mirror 113 again as reflected light of the pump light and reflected light of the Stokes light.

The other pump light and the Stokes light divided into two by the half mirror 113 are reflected by the reflection mirror 301 and reflected on the half mirror 113 as reference light for obtaining interference light. It overlaps with light and reflected light of the Stokes light.
The overlapped reference light and reflected light are separated into the interference light of the pump light and the interference light of the Stokes light by a long pass dichroic mirror 302 that reflects light having a wavelength of 1,064 nm or more. The light enters the

detectors

303 and 304.

FIG. 5 is an explanatory diagram showing an example of the relationship between the wavelength variable range of the pump light and the Stokes light, the vibration band in the molecule to be tested, and the wavelength of the anti-Stokes light.
As shown in FIG. 5, the minimum value δ _min and the maximum value δ _max in the range in which the wavelength difference is variable are _expressed by the following equation, where 0 = δ _min <δ _{Let n} <δ _max .
For example, as a vibration band in the molecules of the subject, skeletal vibration band [delta] ₁ of glucose 512cm ^-1, C-O vibrational bands [delta] ₂ of Ruchinoru of 1,050Cm ^-1, and 1,159cm ^-1 lutein C- and C vibration bands δ _3. In this case, the range for varying the wavelength difference, a ^{0cm ^-1 <δ <1,400cm -1.} The wavelength of the pump light changes in the range of 990 nm ≦ λ _pump ≦ 1,064 nm, and the wavelength of the Stokes light changes in the range of 1,150 nm ≧ λ _stokes ≧ 1,064 nm.
Accordingly, the photodetector 303 for detecting the Stokes light outputs a spectral interference signal of 1,064 nm ≦ λ _stokes ≦ 1,150 nm, and the photodetector 304 for detecting the pump light is 1,064 nm ≧ λ A spectral interference signal with _pump ≧ 990 nm is output.

The spectral interference signals are combined by the signal processing unit 400 at a wavelength of 1064 nm where the wavelength difference is 0, and become a spectral interference signal of 990 nm ≦ λ ≦ 1,150 nm. When the spectral interference signal is subjected to inverse Fourier transform, the depth resolution is expressed by the following equation: Δz = (2ln2) / π · (λ ₀ ² /Δλ)=3.16 μm The A line for generating the tomographic image Signal. The tomographic image can be obtained by scanning the measurement of the A line signal in the X direction. Here, ln is a natural logarithm, λ ₀ is the wavelength of the anti-Stokes light, and Δλ is the step when sweeping the wavelengths of the pump light and the Stokes light.

Next, the operation of acquiring the molecular distribution image will be described with reference to FIG.
One of the pump light and the Stokes light split by the half mirror 113 is further split by the half mirror 201.

One of the pump light and the Stokes light separated by the half mirror 201 passes through water 202 and a reflection mirror 203 as an anti-Stokes light generation sample in order to generate reference light of the non-resonant anti-Stokes light. Focused by the lens 213. The non-resonant anti-Stokes light induced at the focal point is reflected by the reflection mirror 203, collected by the lens 213, and again incident on the half mirror 201 as parallel light.

The other pump light and Stokes light bisected by the half mirror 201 are incident on the eyeball unit 20 as the test object via the galvanometer mirrors 115 and 116, and are focused on the crystalline lens of the eyeball unit 20 and are focused on the fundus retina. Reach. The resonance anti-Stokes light is generated from the molecule to be tested that is present in the fundus retina irradiated with the pump light and the Stokes light. The generated resonance anti-Stokes light is collected by the crystalline lens and overlaps with the non-resonance anti-Stokes light as reference light for obtaining interference light on the half mirror 201 as parallel light.

The long-pass dichroic mirror 204 that reflects light having a wavelength of 990 nm or more separates the overlapping resonance anti-Stokes light and non-resonance anti-Stokes light from the pump light and Stokes light that are in the same optical axis direction.
The separated resonance anti-Stokes light and non-resonance anti-Stokes light are separated by a long-pass dichroic mirror 205 that reflects light having a wavelength of 950 nm or more, and the anti-Stokes light (984 nm light) in the vibration mode of the glucose skeleton is glucose resonance. It enters the photodetector 206 as a signal.
The anti-Stokes light (911 nm light) in the rutinol CO vibration mode and the anti-Stokes light (898 nm light) in the lutein CC vibration mode reflected by the long-pass dichroic mirror 205 reflects the light having a wavelength of 905 nm or more. 208, and enters the

photodetectors

209 and 211 as a rutinol resonance signal and a lutein resonance signal, respectively.

As shown in FIG. 5, in the variable range ^{0cm ^-1} <δ ^{<1,400cm -1} in wavelength difference [delta], the resonance anti-Stokes light corresponding to 512cm ^-1 glucose skeleton vibration (wavelength 984 nm) is the Ruchinoru the resonance anti-Stokes light corresponding to 1,050Cm ^-1 of C-O vibrations (wavelength 911nm) is, the resonance anti-Stokes light corresponding to 1,525Cm ^-1 of C-C vibration of lutein (wavelength 898nm) is, It occurs in a range of about ± 5 nm from each central wavelength.
The resonance anti-Stokes light is superimposed on the non-resonance anti-Stokes light as the reference light on the half mirror 201 and detected by

photodetectors

206, 209, and 211.

The outputs from the

photo detectors

206, 209, and 211 are subjected to the removal of DC components by the high-

pass filters

207, 210, and 212 to become spectral interference signals.
When the spectrum interference signal is subjected to inverse Fourier transform, the depth resolution is expressed by the following equation: Δz = (2ln2) / π · (λ ₀ ² /Δλ)=(2ln2)/π·(0.9 ² /0.01)= The A line signal for generating the molecular distribution image is 35 μm. The molecular distribution image can be obtained by scanning the measurement of the A line signal in the X direction.
In the conventional molecular distribution imaging technique using the CARS, scanning in the optical axis direction is necessary using an optical system having a high numerical aperture, but the spectral interference signal of the anti-Stokes light (CARS light) is used. By performing inverse Fourier transform, a mechanism for scanning in the optical axis direction can be eliminated.

By the operation as described above, the molecular distribution image image and the tomographic image in the test subject can be acquired simultaneously.
In addition, by performing optical scanning not only in the X direction but also in the Y direction, a three-dimensional image of the molecular distribution image and a three-dimensional image of the form in the test subject can be acquired simultaneously.

10 Test Subject Visualization Device 20 Eyeball (Test Subject)
DESCRIPTION OF SYMBOLS 100 Light irradiation part 200 Molecular distribution image image generation part 300 Tomographic image generation part 400 Signal processing part 500 Image display part

Claims

A light irradiation unit that varies the wavelength of at least one of pump light and Stokes light generated in the same optical path for each test location of the test target, and irradiates the test target with the pump light and the Stokes light;
A molecular distribution image image generation unit that detects anti-Stokes light generated from the test object according to a wavelength difference between the pump light and the Stokes light, and generates a molecular distribution image image based on the anti-Stokes light;
Detecting at least one of reflected light from the test subject when irradiated with the pump light, and reflected light from the test subject when irradiated with the Stokes light, and based on the detected reflected light A tomographic image generator for generating a tomographic image of the test object;
A test object visualization device comprising: an image display unit that displays at least one of the generated molecular distribution image and the tomographic image.
In the range in which the light irradiator varies the wavelength of the pump light and the wavelength of the Stokes light, the pump light and the Stokes light are set to be 0 so that the wavelength difference between the pump light and the Stokes light becomes zero. Irradiate the subject,
Data based on the reflected light from the test subject when the tomographic image generation unit irradiates the pump light, and data based on the reflected light from the test subject when the Stokes light is irradiated, The test object visualization apparatus according to claim 1, wherein the tomographic image is generated based on data combined at a wavelength at which the wavelength difference is zero.
3. The test according to claim 1, wherein the molecular distribution image generation unit performs an inverse Fourier transform calculation process on a spectral interference signal obtained by using the anti-Stokes light as interference light and spectrally separating the interference light. Object visualization device.
The tomographic image generation unit uses interference light as at least one of the reflected light from the test subject when irradiated with the pump light and the reflected light from the test subject when irradiated with the Stokes light. The test object visualization apparatus according to claim 1, wherein an arithmetic process of inverse Fourier transform is performed on a spectrum interference signal obtained by separating the interference light.
The light irradiator is
An optical parametric crystal that converts a wavelength of the light according to an incident angle of the light, and an optical confinement device that confines the light;
The test object visualization apparatus according to claim 1, further comprising: an optical resonator that shares the optical parametric crystal with the optical confinement device and amplifies light having a wavelength converted by the optical parametric crystal.
The said light irradiation part varies the wavelength of the said pump light and the wavelength of the said Stokes light so that the vibration band in the molecule | numerator which the said test subject has may correspond with the said wavelength difference. Test subject visualization device.
The test subject visualization apparatus according to claim 6, wherein the molecule of the test subject is at least one of glucose, rutinol, and lutein.